Polarized electric bell.



No. 800,946. PATENTED OUT. 3, 1905. S. U SHAFFNER.

POLARIZED ELECTRIC BELL.

APPLICATION FILED JULY 15,1903.

iw mmE y INVENTOR W 7 a).

A ttorney UNITED STATES PATENT OFFICE.

POLARIZED ELECTRIC BELL.

Specification of Letters Patent.

Patented Oct. 3, 1905.

Applicatinn filed July 15, 1903' Serial NO. 166563- To a, 11/71/0712 it may concern:

Be it known that I, SAMUEL C. SHAFFNER, a citizen of the United States, residing at Mobile,in the county of Mobile and State of Alabama, have invented certain new and useful Improvements in Polarized Electric Bells; and I do declare that the following is a full, clear, and exact description of the invention, which will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to improvements in polarized electric bells of that type in which the armature of a temporary magnet vibrates between the poles of a permanent magnet.

The objects of the invention are to produce a bell having means for readily removing the permanent magnet and which is simple in construction, cheap to manufacture, and of pleasing appearance.

The invention consists in providing a baseplate of metal, but preferably of cast-iron, upon which are supported the bells, perma nent magnet, and the vibrating armature. The magnet is of the common horseshoe shape formed of a single piece of bent steel of rectangular crosssection. This magnet is removably secured to the base-plate by en gagement with the pole-pieces and a standard and is fastened in place by the coverplate, which is secured to the base by means of screws and engages at its free ends with the pole-pieces cast integral with the base. The pole-pieces are of larger cross-section than the magnet and serve to bring the magnetic poles closer together, with a shorter break in the magnetic circuit than if such pole-pieces were not used. They also permit of a smaller and lighter armature, the preferred form consisting of a simple stamping. The armature and also its excitingspool are carried upon the same supports which support the magnet and are so arranged that the spool will be within the magnet and its armature between the pole-pieces.

In order to better understand the invention, attention is called to the accompanying drawings, in which- Figure 1 represents a front View of the complete bell. Fig. 2 is a perspective view of the base. Fig. 3 is a section taken on the line 3 3 of Fig. 1; and Fig. 4 is a section, similar to Fig. 3, of a modification.

In all of the several views like parts are designated by identical numerals of reference.

The base 1, preferably of cast-iron, is of the same general shape as the permanent magnet 2, but with the addition of the arms 3 and 4, supporting the bells 5 5, and lugs 6 6 6, having screw-openings for attaching the base to its supporting-backing. The base has also formed integrally with it the pole-pieces 7 7 and a standard 8, carrying a supportingbracket 9 for the armature. Upon the base are a pair of binding-screws 10, serving as means for the attachment of the outside circuit and the leading in wires 11. The bracket 9 has screwopenings formed therein, to which the supporting-spring 13 of the armature 14 is secured. The armature passes through the spool or bobbin 15 and carries a hammer 16. The spool or bobbin is secured in place between the pole-pieces 7 7 and the bracket 9 and is prevented from falling out by the cover 18. The pole-pieces and stand ards are provided with screw-holes 19 for the admission of screws 20 for securing the cover, and with it the magnet and coil, in place. The covering-plate 18 has formed upon one edge a lip or finger 21, which engages with the magnet and assists to retain it in position. The armature may have adjacent to the polepieces copper or brass rivets 22, which prevent sticking of the armature to either of the pole pieces.- These rivets project a short distance beyond each side of the armature, as shown.

In lieu of the armaturesupporting spring 13 the construction shown in Fig. 4 may be employed. In the modified form trunnions are used, which may consist of pointed screws 23 24, which engage within depressions or notches 25 26 in the armature. These screws pass through threaded openings in lugs 27 28, cast integrally with the frame. Each screw may be provided with a notched head 29 for adjustment.

The operation in view of the preceding dcscription is obvious, it being understood that the spool 15 and armature 14 are alternately excited with current of opposite polarity, causing the armature to be intermittently attracted to opposite poles. The per manent magnet when it becomes weakened may be removed by first taking out the supporting screws 20 and first removing the cover 18 without otherwise disarranging the apparatus. The armature once adjusted in proper relation to the pole-pieces will not be required to be again adjusted after a new magnet is in place. The leading-in wires also will not be disturbed. To secure the best results, it is necessary to so proportion the pole-pieces 7 7 that they closely engage with the inside of the free extremities ofthe magnet. This will interrupt the magnetic current to but a very small degree. It the pole -pieces be so located that it is necessary to separate the legs of the magnet a small ex tent to allow it to be placed in position, there will always be close contact of the magnet with the pole-pieces.

In accordance with the patent statutes I have described the principle of operation of the invention, together with the apparatus which I now consider to represent the best embodiment thereof; but I desire to have it understood that the apparatus shown is only illustrative and that the invention can be carried out by other means.

Having now described my invention, what I claim, and desire to secure by Letters Patent, is-

1. In a polarized electric mechanism, the combination with a cast-metal base, of polepieces formed integral therewith, and a permanent magnet removably secured thereto, in engagement with said pole-pieces, substantially as described;

2. In a polarized. electric mechanism, the combination with a cast-metal base, of bellsupports thereon, pole-pieces formed integral therewith, and a permanent magnet removably secured thereto, in engagement with said pole-pieces, substantially as described.

3. An electric mechanism, comprising in combination a metal base, pole-pieces thereon, an armature-support, an armature thereon, a coil, a permanent magnet secured thereto in engagement with said pole-pieces, forming the outer casing to protect the coil and parts contained therein, and a coverplate covering and holding said magnet in position, substantially as described.

4. In an electric mechanism, the combination with a base, of pole-pieces thereon, a permanent magnet upon the base and engaging with the pole-pieces, and a coverplate secured to the pole-pieces and engaging with the magnet to retain it in place, substantially as described.

5. In an electric mechanism, the combination with a base, of pole-pieces thereon, a permanent magnet upon the base and engaging with the pole-pieces, and a cover with a depending lip 21, engaging with the magnet to retain it in place, substantially as described. 4

6. In a polarized electrical mechanism, the combination with a metal base, pole-pieces and an armature-support integral therewith, an oscillating armature elastically secured to the armature-support, a stationary coil surrounding the armature and engaging the armature-support and pole-pieces, of a permanent magnet engaging the armature-support and pole-pieces and forming a covering for the top and sides of the mechanism, and a plate covering the front of the mechanism, substantially as described.

This specification signed and witnessed this 25th day of June, 1903.

SAMUEL C. SHAFFNER.

Witnesses:

E. II. MOBEE, WM. L. TIMBERLAKE. 

